1. Field of the Invention
The present invention is generally concerned with clutches intended in particular for equipping automobile vehicles and comprising in particular an annular part called the cover.
2. Description of the Prior Art
There are already known clutches of the kind comprising a first plate called the pressure plate, constrained to rotate with a cover and movable axially relative thereto, controllable axially acting elastic means disposed between said cover and said pressure plate urging the latter away from said cover, a friction disk adapted to be constrained to rotate with a first shaft, in general a driven shaft, and a second plate called the reaction plate adapted to be constrained to rotate with a second shaft, in general a driving shaft.
It is usual practice to assemble together the cover, the pressure plate and the controllable action elastic means disposed between them to make up a unit assembly called the clutch cover assembly ready for subsequent direct mounting as such on the associated reaction plate after fitting the friction disk.
This mounting on the reaction plate is usually effected by means of fastening members, such as screws, conveniently distributed along the outside periphery of the cover and substantially radial fastening areas on the cover which naturally have to project externally of the pressure plate and the friction disk. This results in a clutch cover assembly of the kind described, for example, in French patent application 81 11596 (U.S. equivalent Ser. No. 386,397) in which the stamped cover has a considerably greater diameter than the friction disk and the pressure plate, resulting in an increase in the weight, inertia and overall dimensions of the assembly which may be undesirable, especially in heavy trucks and like vehicles.
There is also known from U.S. Pat. No. 4,069,905 a clutch cover assembly fabrication technique which enbles the diameter of the cover to be limited to a value only slightly greater than the diameter of the pressure plate and the friction disk; this technique essentially consists in providing substantially radial fastening areas on the cover by the provision of spacers projecting axially from these areas and attached to said areas as by welding, for example, each of these spacers featuring at a distance from the fastening area from which it projects a bearing surface through which it is adapted to bear radially on the associated reaction plate. However, because of the spacers this technique entails dividing the cover into a certain number of supplementary parts, which has the disadvantage of complicating the structure, and fabrication is difficult to mechanize by virtue of the abundance of parts.
An objective of the present invention is to circumvent the various disadvantages mentioned hereinabove by providing for limiting the overall radial dimension of the cover whilst eliminating the necessity to divide it into separate parts.